SELECT T.*,
  T_USER_GROUP.CODE AS USER_GROUP_CODE,
  T_USER_GROUP.NAME AS USER_GROUP_NAME,
  T_USER.CODE       AS USER_CODE,
  T_USER.NAME       AS USER_NAME
FROM C1_US_GROUP_USER T
LEFT JOIN C1_USER_GROUP T_USER_GROUP
ON (T_USER_GROUP.id = t.user_group_id)
LEFT JOIN C1_USER T_USER
ON (T_USER.id = t.user_id)
WHERE T.id          = :id